Actual IOL position (ALP) and effective lens position (ELP) in eyes with 0.5 D postoperative refractive error

Session Details

Session Title: Presented Poster Session: Imaging

Venue: Poster Village: Pod 3

First Author: : P.Fedor USA

Co Author(s): :                           

Abstract Details

Purpose:

To evaluate if errors of IOL power calculation formulas larger than 0.5 diopters can be explained by quantitative ultrasound biomicroscopy (Q-UBM) of the anterior segment before and after cataract surgery.

Setting:

Great Lakes Eye Consultants - Private Practice

Methods:

This is retrospective study of 30 eyes of 30 patients with less usual biometry (many biometric outliers) who underwent Lenstar interferometry and ultrasound biomicroscopy imaging of the entire anterior segment both before and after cataract surgery. Eyes were divided in 9 biometric groups and outliers (Fedor’s classification). New Quantitative analysis of the anterior segment anatomy (Q-UBM) was used to analyze anterior segment anatomy. The ALP form Lenstar and Q-UBM was compared to predicted ELP position.

Results:

The postoperative anterior chamber depth (ACD) using Lenstar highly correlated with Q-UBM. The postoperative error of predicted refractions of 0.5 D or more was identified in 9 out of 30 eyes. Different ALP as compared to ELP was a factor in 5 eyes. The actual IOL position on AS UBM imaging explained the large myopic postoperative errors in some small eyes. The syndrome of Posterior Volume Enlargement (PVE) is described based on Q-UBM.

Conclusions:

Incorrect ELP prediction is an important factor in most eyes with postoperative errors of 0.5 D or more, especially in small hyperopic eyes. Q-UBM is suitable method to quantitatively analyze IOL position and anterior segment anatomy, diagnose PVE and potentially improve prediction of IOL position in small hyperopic eyes and biometric outliers.

Financial Disclosure:

None